--- /dev/null
+/*
+ Write a packet
+
+ Copyright (C) Amitay Isaacs 2015
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "replace.h"
+#include "system/network.h"
+
+#include <talloc.h>
+#include <tevent.h>
+
+#include "lib/util/tevent_unix.h"
+
+#include "pkt_write.h"
+
+/*
+ * Write a packet
+ */
+
+struct pkt_write_state {
+ int fd;
+ uint8_t *buf;
+ size_t buflen, offset;
+};
+
+struct tevent_req *pkt_write_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ int fd, uint8_t *buf, size_t buflen)
+{
+ struct tevent_req *req;
+ struct pkt_write_state *state;
+
+ req = tevent_req_create(mem_ctx, &state, struct pkt_write_state);
+ if (req == NULL) {
+ return NULL;
+ }
+
+ state->fd = fd;
+ state->buf = buf;
+ state->buflen = buflen;
+ state->offset = 0;
+
+ return req;
+}
+
+void pkt_write_handler(struct tevent_context *ev, struct tevent_fd *fde,
+ uint16_t flags, struct tevent_req *req)
+{
+ struct pkt_write_state *state = tevent_req_data(
+ req, struct pkt_write_state);
+ ssize_t nwritten;
+
+ nwritten = write(state->fd, state->buf + state->offset,
+ state->buflen - state->offset);
+ if ((nwritten == -1) && (errno == EINTR)) {
+ /* retry */
+ return;
+ }
+ if (nwritten == -1) {
+ tevent_req_error(req, errno);
+ return;
+ }
+ if (nwritten == 0) {
+ /* retry */
+ return;
+ }
+
+ state->offset += nwritten;
+ if (state->offset < state->buflen) {
+ /* come back later */
+ return;
+ }
+
+ tevent_req_done(req);
+}
+
+ssize_t pkt_write_recv(struct tevent_req *req, int *perrno)
+{
+ struct pkt_write_state *state = tevent_req_data(
+ req, struct pkt_write_state);
+
+ if (tevent_req_is_unix_error(req, perrno)) {
+ return -1;
+ }
+
+ return state->offset;
+}
--- /dev/null
+/*
+ API for writing a packet
+
+ Copyright (C) Amitay Isaacs 2015
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __CTDB_PKT_WRITE_H__
+#define __CTDB_PKT_WRITE_H__
+
+#include <talloc.h>
+#include <tevent.h>
+
+/**
+ * @file pkt_write.h
+ *
+ * @brief Write a packet.
+ *
+ * Write a complete packet with possibly multiple system calls.
+ */
+
+/**
+ * @brief Start async computation to write a packet
+ *
+ * This returns a tevent request to write a packet to given fd. The fd
+ * should be nonblocking. Freeing this request will free all the memory
+ * associated with the request.
+ *
+ * @param[in] mem_ctx Talloc memory context
+ * @param[in] ev Tevent context
+ * @param[in] fd The non-blocking file/socket descriptor to write to
+ * @param[in] buf The data
+ * @param[in] buflen The size of the data
+ * @return new tevent request or NULL on failure
+ */
+struct tevent_req *pkt_write_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ int fd, uint8_t *buf, size_t buflen);
+
+/**
+ * @brief Function to actually write data to the socket
+ *
+ * This function should be called, when tevent fd event is triggered
+ * for TEVENT_FD_WRITE event. This function has the syntax of
+ * tevent_fd_handler_t. The private_data for this function is the tevent
+ * request created by pkt_write_send function.
+ *
+ * @param[in] ev Tevent context
+ * @param[in] fde Tevent fd context
+ * @param[in] flags Tevent fd flags
+ * @param[in] req The active tevent request
+ */
+void pkt_write_handler(struct tevent_context *ev, struct tevent_fd *fde,
+ uint16_t flags, struct tevent_req *req);
+
+/**
+ * @brief Packet is sent
+ *
+ * This function returns the number of bytes written.
+ *
+ * @param[in] req Tevent request
+ * @param[out] perrno errno in case of failure
+ * @return the number of bytes written, or -1 on failure
+ */
+ssize_t pkt_write_recv(struct tevent_req *req, int *perrno);
+
+#endif /* __CTDB_PKT_WRITE_H__ */
--- /dev/null
+/*
+ packet write tests
+
+ Copyright (C) Amitay Isaacs 2015
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "replace.h"
+#include "system/filesys.h"
+
+#include <assert.h>
+
+#include "common/pkt_read.c"
+#include "common/pkt_write.c"
+
+struct writer_state {
+ struct tevent_context *ev;
+ int fd;
+ uint8_t *buf;
+ size_t buflen;
+ int count;
+ struct tevent_req *subreq;
+};
+
+static void writer_next(struct tevent_req *subreq);
+
+static struct tevent_req *writer_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ int fd, uint8_t *buf, size_t buflen)
+{
+ struct tevent_req *req, *subreq;
+ struct writer_state *state;
+
+ req = tevent_req_create(mem_ctx, &state, struct writer_state);
+ if (req == NULL) {
+ return NULL;
+ }
+
+ state->ev = ev;
+ state->fd = fd;
+ state->buf = buf;
+ state->buflen = buflen;
+ state->count = 0;
+
+ subreq = pkt_write_send(state, state->ev, state->fd,
+ state->buf, state->buflen);
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
+ }
+
+ state->subreq = subreq;
+ tevent_req_set_callback(subreq, writer_next, req);
+ return req;
+}
+
+static void writer_next(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct writer_state *state = tevent_req_data(
+ req, struct writer_state);
+ ssize_t nwritten;
+ int err = 0;
+
+ nwritten = pkt_write_recv(subreq, &err);
+ TALLOC_FREE(subreq);
+ state->subreq = NULL;
+ if (nwritten == -1) {
+ tevent_req_error(req, err);
+ return;
+ }
+
+ if (nwritten != state->buflen) {
+ tevent_req_error(req, EIO);
+ return;
+ }
+
+ state->count++;
+ if (state->count >= 1000) {
+ tevent_req_done(req);
+ return;
+ }
+
+ subreq = pkt_write_send(state, state->ev, state->fd,
+ state->buf, state->buflen);
+ if (tevent_req_nomem(subreq, req)) {
+ return;
+ }
+
+ state->subreq = subreq;
+ tevent_req_set_callback(subreq, writer_next, req);
+}
+
+static void writer_recv(struct tevent_req *req, int *perr)
+{
+ struct writer_state *state = tevent_req_data(
+ req, struct writer_state);
+ int err = 0;
+
+ if (state->subreq != NULL) {
+ *perr = -1;
+ return;
+ }
+
+ if (tevent_req_is_unix_error(req, &err)) {
+ *perr = err;
+ return;
+ }
+
+ *perr = 0;
+}
+
+static void writer_handler(struct tevent_context *ev, struct tevent_fd *fde,
+ uint16_t flags, void *private_data)
+{
+ struct tevent_req *req = talloc_get_type_abort(
+ private_data, struct tevent_req);
+ struct writer_state *state = tevent_req_data(
+ req, struct writer_state);
+
+ assert(state->subreq != NULL);
+ pkt_write_handler(ev, fde, flags, state->subreq);
+}
+
+static void writer(int fd)
+{
+ TALLOC_CTX *mem_ctx;
+ struct tevent_context *ev;
+ struct tevent_fd *fde;
+ struct tevent_req *req;
+ uint8_t buf[1024*1024];
+ size_t buflen;
+ size_t pkt_size[4] = { 100, 500, 1024, 1024*1024 };
+ int i, err;
+
+ mem_ctx = talloc_new(NULL);
+ assert(mem_ctx != NULL);
+
+ ev = tevent_context_init(mem_ctx);
+ assert(ev != NULL);
+
+ for (i=0; i<1024*1024; i++) {
+ buf[i] = i%256;
+ }
+
+ for (i=0; i<4; i++) {
+ buflen = pkt_size[i];
+ *(uint32_t *)buf = buflen;
+
+ req = writer_send(mem_ctx, ev, fd, buf, buflen);
+ assert(req != NULL);
+
+ fde = tevent_add_fd(ev, mem_ctx, fd, TEVENT_FD_WRITE,
+ writer_handler, req);
+ assert(fde != NULL);
+
+ tevent_req_poll(req, ev);
+
+ writer_recv(req, &err);
+ assert(err == 0);
+
+ talloc_free(fde);
+ talloc_free(req);
+ }
+
+ close(fd);
+
+ talloc_free(mem_ctx);
+}
+
+struct reader_state {
+ struct tevent_context *ev;
+ int fd;
+ uint8_t buf[1024];
+ struct tevent_req *subreq;
+};
+
+static ssize_t reader_more(uint8_t *buf, size_t buflen, void *private_data);
+static void reader_done(struct tevent_req *subreq);
+
+static struct tevent_req *reader_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ int fd)
+{
+ struct tevent_req *req, *subreq;
+ struct reader_state *state;
+
+ req = tevent_req_create(mem_ctx, &state, struct reader_state);
+ if (req == NULL) {
+ return NULL;
+ }
+
+ state->ev = ev;
+ state->fd = fd;
+
+ subreq = pkt_read_send(state, state->ev, state->fd, 4,
+ state->buf, 1024, reader_more, NULL);
+ if (tevent_req_nomem(subreq, req)) {
+ tevent_req_post(req, ev);
+ }
+
+ state->subreq = subreq;
+ tevent_req_set_callback(subreq, reader_done, req);
+ return req;
+}
+
+static ssize_t reader_more(uint8_t *buf, size_t buflen, void *private_data)
+{
+ uint32_t pkt_len;
+
+ if (buflen < sizeof(pkt_len)) {
+ return sizeof(pkt_len) - buflen;
+ }
+
+ pkt_len = *(uint32_t *)buf;
+ return pkt_len - buflen;
+}
+
+static void reader_done(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct reader_state *state = tevent_req_data(
+ req, struct reader_state);
+ ssize_t nread;
+ uint8_t *buf;
+ bool free_buf;
+ int err = 0;
+
+ nread = pkt_read_recv(subreq, state, &buf, &free_buf, &err);
+ TALLOC_FREE(subreq);
+ state->subreq = NULL;
+ if (nread == -1) {
+ if (err == EPIPE) {
+ tevent_req_done(req);
+ } else {
+ tevent_req_error(req, err);
+ }
+ return;
+ }
+
+ if (free_buf) {
+ talloc_free(buf);
+ }
+
+ subreq = pkt_read_send(state, state->ev, state->fd, 4,
+ state->buf, 1024, reader_more, NULL);
+ if (tevent_req_nomem(subreq, req)) {
+ return;
+ }
+
+ state->subreq = subreq;
+ tevent_req_set_callback(subreq, reader_done, req);
+}
+
+static void reader_recv(struct tevent_req *req, int *perr)
+{
+ struct reader_state *state = tevent_req_data(
+ req, struct reader_state);
+ int err = 0;
+
+ if (state->subreq != NULL) {
+ *perr = -1;
+ }
+
+ if (tevent_req_is_unix_error(req, &err)) {
+ *perr = err;
+ return;
+ }
+
+ *perr = 0;
+}
+
+static void reader_handler(struct tevent_context *ev, struct tevent_fd *fde,
+ uint16_t flags, void *private_data)
+{
+ struct tevent_req *req = talloc_get_type_abort(
+ private_data, struct tevent_req);
+ struct reader_state *state = tevent_req_data(
+ req, struct reader_state);
+
+ assert(state->subreq != NULL);
+ pkt_read_handler(ev, fde, flags, state->subreq);
+}
+
+static void reader(int fd)
+{
+ TALLOC_CTX *mem_ctx;
+ struct tevent_context *ev;
+ struct tevent_fd *fde;
+ struct tevent_req *req;
+ int err;
+
+ mem_ctx = talloc_new(NULL);
+ assert(mem_ctx != NULL);
+
+ ev = tevent_context_init(mem_ctx);
+ assert(ev != NULL);
+
+ req = reader_send(mem_ctx, ev, fd);
+ assert(req != NULL);
+
+ fde = tevent_add_fd(ev, mem_ctx, fd, TEVENT_FD_READ,
+ reader_handler, req);
+ assert(fde != NULL);
+
+ tevent_req_poll(req, ev);
+
+ reader_recv(req, &err);
+ assert(err == 0);
+
+ close(fd);
+
+ talloc_free(mem_ctx);
+}
+
+static bool set_nonblocking(int fd)
+{
+ int v;
+
+ v = fcntl(fd, F_GETFL, 0);
+ if (v == -1) {
+ return false;
+ }
+ if (fcntl(fd, F_SETFL, v | O_NONBLOCK) == -1) {
+ return false;
+ }
+ return true;
+}
+
+int main(void)
+{
+ int fd[2];
+ int ret;
+ pid_t pid;
+
+ ret = pipe(fd);
+ assert(ret == 0);
+
+ pid = fork();
+ assert(pid != -1);
+
+ if (pid == 0) {
+ /* Child process */
+ close(fd[0]);
+ writer(fd[1]);
+ exit(0);
+ }
+
+ close(fd[1]);
+ if (!set_nonblocking(fd[0])) {
+ exit(1);
+ }
+
+ reader(fd[0]);
+
+ return 0;
+}